It's not as if London has gotten suddenly more dangerous. But for someone like Abramovich, who is worth billions, his family could face security threats if they were crammed onto the Jubilee Line, a main artery to the games.
PSI offered reporters a demonstration ride on the Thames, offering a taste of how the super rich might get to their seats at the beach volleyball competition.
It started with champagne at the Savoy, London's elegant hotel. Then a trip on a rigid inflatable boat down the Thames followed the bubbly, a zippy excursion that could give Disneyland ideas on roller coasters and white water rafting. Envision ex-Marines re-living glory days with a high-powered boat to play with, you get the picture.
PSI declined to talk about prices — saying that depends on what the client wants and how complicated the security arrangements are.
At this level, talking about money is a tad crass, anyway.
But no matter what, they offer great scenery. The Thames will provide the images of London that viewers around the world want to see this summer and will remember for years to come.
"The river is the very reason for London," Blyth, the naval historian, said. "London exists entirely because of the Thames."
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.